As is shown in FIG. 1, two elements 10, 10′ positioned flush with one another are assembled with at least one blind fastener in the form of a rivet 12 comprising a cylindrical body 14 having two heads 16, 16′, one at either end. For each rivet, the first element to be assembled 10 is furnished with a hole 18 located in the continuation of a hole 18′ created in the first element to be assembled 10′, in which cylindrical body 14 of the rivet is seated. In addition, the first element to be assembled 10 has a bearing surface 20 against which one of the heads 16 of the rivet may be flattened, and the second element to be assembled 10′ has a bearing surface 20′ against which the other head 16′ of the rivet is flattened.
When it is put in place, the rivet is deformed particularly in terms of its heads 16 and 16′, and cylindrical body 14 tends to expand to create a tight, adjusted fit between said cylindrical body 14 and holes 18, 18′. Accordingly, after the rivet has been put in place, elements 10 and 10′ are held together by heads 16, 16′ of the rivet and also by the adjusted tight fit between cylindrical body 14 of the rivet and holes 18, 18′.
As described in document EP-898.063, blind fasteners may be used to create a join between a flange plate 22 and an acoustic treatment panel 24 provided on the air intake of an aircraft engine nacelle. An acoustic treatment panel 24 comprises in known manner a sound damping layer 26 that is in contact with the aerodynamic airflows, a cellular structure 28 and a reflective layer 30. In this application, rivet 12 provides the join between reflective layer 30 and a flange 22, and one of the heads 16′ of the rivet is buried in cellular structure 28.
When it becomes necessary to remove panel 24 and flange 22, rivet 12 has to be destroyed. For this purpose a drill equipped with a bit 32 having a diameter essentially equal to that of holes 18, 18′ is used to partly destroy one of the heads 16 so that the body 14 of the rivet can be separated. When the bit reaches a certain depth, the ring-shaped remainder of head 16 separated from body 14. However, it is necessary to continue drilling and apply a certain pressure to the remainder of the rivet in order to detach it given the tight adjusted fitting between the body 14 of the rivet and holes 18, 18′. After a certain depth has been passed, the pressure applied by the operator causes a sudden break in the attachment between the rivet body and the holes in the parts to be joined.
When this operation is carried out on several rivets in succession, it can happen that the operator is carried forward by the impetus of his own efforts and does not restrain the drill, with the result that rivet 12 may pass through the cellular structure and damage the acoustic treatment panel by denting it as shown in FIG. 2. If this dent is too pronounced, it then becomes necessary to repair panel 24, or even replace it. Therefore, in order to limit the risk of damaging the panel the disassembly operation must be carried out with extreme care, which tends to increase the time required for the operation and extend the period for which the aircraft is out of service.
Accordingly, at least one purpose is to alleviate the drawbacks of the prior art by suggesting a method for destroying a blind fastener that limits the risk of damaging the elements that are joined by said fastener. In addition, other purposes, desirable features and characteristics will become apparent from the subsequent summary and detailed description, and the appended claims, taken in conjunction with the accompanying drawings and this background.